MANILA (Reuters) - Philippine miners claim the government's environmental crackdown is a "demolition campaign" against mineral producers and are seeking to meet with President Rodrigo Duterte amid a spate of shutdowns stemming from the probe, an industry official said.

Duterte's seven-week old government has so far suspended 10 mines, eight of them nickel, for environmental infractions, sowing fear among large-scale miners in the world's top nickel producer that more shutdowns may follow.

The country's mining industry expects to push ahead with $23-billion worth of new investments from this year through 2020, but this "spirit of optimism is being shattered by ... a very unstable policy outlook," Benjamin Philip Romualdez, president of the Chamber of Mines of the Philippines, said at an industry conference on Wednesday.

"Notwithstanding the ongoing demolition campaign that is maliciously maligning the true nature of legitimate mining, we will not allow anyone, to destroy our industry ... and we will all do this under the rule of law," said Romualdez.

It was the first time that domestic miners have spoken strongly against the government's tough clampdown.

Duterte, who was invited to speak at the conference but did not attend, has previously warned miners to strictly follow tighter environmental rules or shut down, saying the nation could survive without a mining industry.

The crackdown on the sector is being led by Environment and Natural Resources Secretary Regina Lopez, an environmentalist who thinks open-pit mining is "madness".

Romualdez, also the president of gold-and-nickel producer Benguet Corp that is pursuing a $350-million expansion of one of its gold mines, has appealed for an industry meeting with Duterte so that future policies could be "based on science and hard facts and not on mere slogans of hardline ideology".

'NOT LUMPED IN ONE BASKET'

Miners say the government should zero in on illegal small-scale miners causing the most environmental harm.

"We can't be lumped all in one basket. There are those that do really well and there are those that don't do well and the government should be able to distinguish," Nickel Asia Corp Chief Executive Gerard Brimo said.

Leo Jasareno, who is leading the government's environmental audit, said there was no plan to shut the mining sector.

"The purpose of the audit is to ensure that only responsible mining is pursued," Jasareno told Reuters by phone.

Congressman Erlpe John Amante, who has called for a ban on exports of unprocessed minerals, says there is a need "to make mining more relevant".

Unless miners invest in processing plants, the Philippines may be better off shutting its mines given the sector's modest contribution to the economy, Amante has said.